System and method for delivering satellite services at multiple security levels

ABSTRACT

The disclosed embodiments relate to a system and method for delivering satellite services at multiple security levels. More specifically, there is provided a method comprising determining a level of security supported by a first set top box, encoding a first IP packet containing a satellite service using the level of security supported by the first set top box, transmitting the first IP encoded packet to the first set top box, determining a level of security supported by a second set top box, wherein the level of security supported by the second set top box is different from the level of security of the first set top box, encoding a second IP packet containing a satellite service using the level of security supported by the second set top box; and transmitting the second encoded IP packet to the second set top box.

This application claims the benefit, under 35 U.S.C. §365 ofInternational Application PCT/US2005/038751, filed Oct. 26, 2005, whichwas published in accordance with PCT Article 21(2) on May 3, 2007 inEnglish.

FIELD OF THE INVENTION

The present invention relates generally to transmitting video or otherservices data over a network. More specifically, the present inventionrelates to a system for delivering satellite services at multiplesecurity levels.

BACKGROUND OF THE INVENTION

This section is intended to introduce the reader to various aspects ofart, which may be related to various aspects of the present inventionthat are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentinvention. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

As most people are aware, satellite television systems, such as DirecTV,have become much more widespread over the past few years. In fact, sincethe introduction of DirecTV in 1994, more than twelve million Americanhomes have become satellite TV subscribers. Most of these subscriberslive in single-family homes where satellite dishes are relatively easyto install and connect. For example, the satellite dish may be installedon the roof of the house.

Many potential subscribers, however, live or temporarily reside inmulti-dwelling units (“MDUs”), such as hotels or high-rise apartmentbuildings. Unfortunately, there are additional challenges involved withproviding satellite TV services to the individual dwelling units withinan MDU. It may be impractical and/or extremely expensive to provide andconnect one satellite dish per dwelling. For example, in a high-riseapartment building with one thousand apartments, it may be impracticalto mount one thousand satellite dishes on the roof of the building. Someconventional systems have avoided these issues by converting the digitalsatellite television signal into an analog signal that can betransmitted via a single coaxial cable to a plurality of dwellings.These systems, however, offer limited channels, have reduced qualitycompared to all-digital systems, and cannot provide the satellite TVexperience that users who live in single family homes are accustomed.

An improved system and/or method for providing satellite TV to amulti-dwelling unit is desirable.

SUMMARY OF THE INVENTION

Certain aspects commensurate in scope with the originally claimedinvention are set forth below. It should be understood that theseaspects are presented merely to provide the reader with a brief summaryof certain forms the invention might take and that these aspects are notintended to limit the scope of the invention. Indeed, the invention mayencompass a variety of aspects that may not be set forth below.

The disclosed embodiments relate to a system and method for deliveringsatellite services at multiple security levels. More specifically, thereis provided a method comprising determining a level of securitysupported by a first set top box (22 a), encoding a first IP packetcontaining a satellite service using the level of security supported bythe first set top box (22 a), transmitting the first IP encoded packetto the first set top box (22 a), determining a level of securitysupported by a second set top box (22 b), wherein the level of securitysupported by the second set top box (22 b) is different from the levelof security of the first set top box (22 a), encoding a second IP packetcontaining a satellite service using the level of security supported bythe second set top box (22 b); and transmitting the second encoded IPpacket to the second set top box (22 b).

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the invention may become apparent upon reading thefollowing detailed description and upon reference to the drawings inwhich:

FIG. 1 is a block diagram of an exemplary satellite television over IPsystem in accordance with one embodiment of the present invention;

FIG. 2 is another embodiment of the exemplary satellite television overIP system illustrated in FIG.; and

FIG. 3 is a block diagram of an exemplary satellite gateway of thepresent invention.

DETAILED DESCRIPTION

One or more specific embodiments of the present invention will bedescribed below. In an effort to provide a concise description of theseembodiments, not all features 6 f an actual implementation are describedin the specification. It should be appreciated that in the developmentof any such actual implementation, as in any engineering or designproject, numerous implementation-specific decisions must be made toachieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

Turning to FIG. 1, a block diagram of an exemplary satellite televisionover IP system in accordance with one embodiment is illustrated andgenerally designated by a reference numeral 10. As illustrated, in oneembodiment, the system 10 may include one or more satellite dishes 12 athrough 12 m, a head-end unit, such as a satellite gateway 14, an IPdistribution network 20, and one or more set top boxes (“STBs”) 22 athrough 22 n. Those of ordinary skill in the art, however, willappreciate that the embodiment of the system 10 illustrated in FIG. 1 ismerely one potential embodiment of the system 10. As such, in alternateembodiments, the illustrated components of the system 10 may berearranged or omitted or additional components may be added to thesystem 10. For example, with minor modifications, the system 10 mayconfigured to distributed non-satellite video and audio services.

The satellite dishes 12 a-12 m may be configured to receive video,audio, or other types of television-related data that is transmittedfrom satellites orbiting the earth. As will be described further below,in one embodiment the satellite dishes 12 a-12 m are configured toreceive DirecTV programming over KU band from 10.7 to 12.75 Gigahertz(“GHz”). In alternate embodiments, however, the satellite dishes 12 a-12m may be configured to receive other types of direct broadcastsatellites (“DBS”) or television receive-only (“TVRO”) signal, such asDish Network signals, ExpressVu signals, StarChoice signals, and thelike. In still other non-satellite based systems, the satellite dishes12 a-12 m may be omitted from the system 10.

In one embodiment, a low noise-block converter (“LNC”) within thesatellite dishes 12 a-12 m receives the incoming signal from theearth-orbiting satellite and converts these incoming signals to afrequency in the L band between 950 and 2150 Megahertz (“MHz”). As willbe described in further detail below with regard to FIG. 2, each of thesatellites 12 a-12 m may be configured to receive one or more incomingsatellite TV signals on a particular frequency (referred to as atransponder) and with a particular polarization and to convert thesesatellite signals to L band signals, each of which may contain aplurality of video or audio signals.

The satellite dishes 12 a-12 m may be configured to transmit the L bandsignals to a head-end unit or gateway server, such as the satellitegateway 14. In alternate, non-satellite embodiments, the head-end unitmay be a cable television receiver, a high definition televisionreceiver, or other video distribution system

The satellite gateway 14 includes a satellite tuning, demodulating, anddemultiplexing module 16 and an IP wrapper module 18. The module 16 maycontain a plurality of tuners, demodulators, and demultiplexers toconvert the modulated and multiplexed L band signals transmitted fromthe satellites 12 a-12 m into a plurality single program transportstreams (“SPTS”), each of which carries a service (e.g., televisionchannel video, television channel audio, program guides, and so forth).In one embodiment, the module 16 is configured to produce a singleprogram transport stream for all of the services received by thesatellite dishes 12 a-12 m. In an alternate embodiment, however, themodule 16 may produce transport streams for only a subset of theservices received by the satellite dishes 12 a-12 m.

The satellite tuning, demodulating, and demultiplexing module 16 maytransmit the SPTS to the IP wrapper module 18. In one embodiment, the IPwrapper module 18 repackages the data within the SPTS into a pluralityof internet protocol (“IP”) packets suitable for transmission over theIP distribution network 20. For example, the IP wrapper module 18 mayconvert DirecTV protocol packets within the SPTS into IP packets. Inaddition, the IP wrapper module 18 may be configured to receive serverrequests from the STBs 22 a-22 n and to multicast (i.e., broadcast toone or more of the STBs 22 a-22 n over an IP address) the IP SPTS tothose STBs 22 a-22 n that had requested the particular service.

In an alternative embodiment, the IP wrapper module 18 may also beconfigured to multicast IP protocol SPTS for services not requested byone of the STBs 22 a-22 n. It should be noted that the modules 16 and 18are merely one exemplary embodiment of the satellite gateway 14. Inalternate embodiments, such as the one described below in regard toFIGS. 2 and 3, the functions of the modules 16 and 18 may beredistributed or consolidated amongst a variety of suitable componentsor modules.

The IP distribution network 20 may include one or more routers,switches, modem, splitters, or bridges. For example, in one embodiment,the satellite gateway 14 may be coupled to a master distribution frame(“MDF”) that is coupled to an intermediate distribution frame (“IDF”)that is coupled to a coax to Ethernet bridge that is coupled to a routerthat is coupled to one or more of the STBs 22 a-22 n. In anotherembodiment, the IP distribution network 20 may be an MDF that is coupledto a Digital Subscriber Line Access Multiplexer (“DSLAM”) that iscoupled to a DSL modem that is coupled to a router. In yet anotherembodiment, the IP distribution network may include a wireless network,such as 802.11 or WiMax network. In this type of embodiment, the STBs 22a-22 n may include a wireless receiver configured to receive themulticast IP packets. Those of ordinary skill in the art will appreciatethat the above-described embodiments are merely exemplary. As such inalternate embodiments, a large number of suitable forms of IPdistribution networks may be employed in the system 10.

The IP distribution network 20 may be coupled to one or more STBs 22a-22 n. The STBs 22 a-22 n may be any suitable type of video, audio,and/or other data receiver capable of receiving IP packets, such as theIP SPTS, over the IP distribution network 20. It will be appreciated theterm set top box (“STB”), as used herein, may encompass not only devicesthat sit upon televisions. Rather the STBs 22 a-22 n may be any suitableform of video or audio receiver, whether internal or external to atelevision, display, or computer, that can be configured to function asdescribed herein—including, but not limited to a video components,computers, wireless telephones, or other forms video recorder. In oneembodiment, the STBs 22 a-22 n may be a DirecTV receiver configured toreceive services, such as video and/or audio, through an Ethernet port(amongst other inputs). In alternate embodiments, the STBs 22 a-22 n maybe designed and/or configured to receive the multicast transmission overcoaxial cable, twisted pair, copper wire, or through the air via awireless standard, such as the I.E.E.E. 802.11 standard.

As discussed above, the system 10 may receive video, audio, and/or otherdata transmitted by satellites in space, and process/convert this datafor distribution over the IP distribution network 20. Accordingly, FIG.2 is another embodiment of the exemplary satellite television over IPsystem 10 in accordance with one embodiment. FIG. 2 illustrates threeexemplary satellite dishes 12 a-12 c. Each of the satellite dishes 12a-12 c may be configured to receive signals from one or more of theorbiting satellites. Those of ordinary skill will appreciate that thesatellites and the signals that are transmitted from the satellites areoften referred to by the orbital slots in which the satellites reside.For example, the satellite dish 12 a is configured to receive signalsfrom a DirecTV satellite disposed in an orbital slot of 101 degrees.Likewise, the satellite dish 12 b receives signals from a satellitedisposed at 119 degrees, and the satellite dish 12 c receives signalsfrom a satellite disposed at orbital slot of 110 degrees. It will beappreciated that in alternate embodiments, the satellite dishes 12 a-12c may receive signals from a plurality of other satellites disclosed ina variety of orbital slots, such as the 95 degree orbital slot. Inaddition, the satellite dishes 12 a-12 c may also be configured toreceive polarized satellite signals. For example, in FIG. 2, thesatellite dish 12 a is configured to receive signals that are both leftpolarized (illustrated in the figure as “101 L”) and right polarized(illustrated as “101 R”).

As described above in regard to FIG. 1, the satellite dishes 12 a-12 cmay receive satellite signals in the KU band and convert these signalsinto L band signals that are transmitted to the satellite gateway 14. Insome embodiments, however, the L band signals produced by the satellitedishes 12 a-12 c may be merged into fewer signals or split into moresignals prior to reaching the satellite gateway 14. For example, asillustrated in FIG. 2, L band signals from the satellite dishes 12 b and12 c may be merged by a switch 24 into a single L band signal containingL band signals from both the satellite at 110 degrees and the satelliteat 119 degrees.

As illustrated, the system 10 may also include a plurality of 1:2splitters 26 a, 26 b, 26 c, and 26 d to divide the L band signalstransmitted from the satellite dishes 12 a-12 c into two L band signals,each of which include half of the services of the pre-split L bandsignal. In alternate embodiments, the 1:2 splitters 26 a-26 b may beomitted or integrated into the satellite gateways 14 a and 14 b.

The newly split L band signals may be transmitted from the 1:2 splitters26 a-26 d into the satellite gateways 14 a and 14 b. The embodiment ofthe system 10 illustrated in FIG. 2 includes two of the satellitegateways 14 a and 14 b. In alternate embodiments, however, the system 10may include any suitable number of satellite gateways 14. For example,in one embodiment, the system may include three satellite gateways 14.

The satellite gateways 14 a and 14 b may then further subdivide the Lband signals and then tune to one or more services on the L band signalto produce one or more SPTS that may be repackaged into IP packets andmulticast over the IP distribution network 20. In addition, one or moreof the satellite gateways 14 a, 14 b may also be coupled to a publicswitch telephone network (“PSTN”) 28. Because the satellite gateways 14a, b are coupled to the PSTN 28, the STBs 22 a-22 n may be able tocommunicate with a satellite service provider through the IPdistribution network 20 and the satellite gateways 14 a, b. Thisfunctionality may advantageously eliminate the need to have eachindividual STBs 22 a-22 n coupled directly to the PSTN 28.

The IP distribution network 20 may also be coupled to an internetservice provider (“ISP”) 30. In one embodiment, the IP distributionnetwork 20 may be employed to provide internet services, such ashigh-speed data access, to the STBs 22 a-22 n and/or other suitabledevices (not shown) that are coupled to the IP distribution network 20.

As described above, the satellite gateways 14 a, b may be configured toreceive the plurality of L band signals, to produce a plurality of SPTS,and to multicast requested SPTS over the IP distribution network 20.Referring now to FIG. 3, a block diagram of an exemplary satellitegateway 14 is shown. As illustrated, the satellite gateway 14 a, bincludes a power supply 40, two front-ends 41 a and 41 b and a back-end52. The power supply 40 may be any one of a number of industry-standardAC or DC power supplies configurable to enable the front-ends 41 a, band the back-end 52 to perform the functions described below.

The satellite gateway 14 a, b may also include two front-ends 41 a, b.In one embodiment, each of the front-ends, 41 a, b may be configured toreceive two L band signal inputs from the 1:2 splitters 26 a-26 d thatwere described above in regards to FIG. 2. For example, the front-end 41a may receive two L band signals from the 1:2 splitter 26 a and thefront-end 41 b may receive two L band signals from the 1:2 splitter 26b. In one embodiment, each of the L band inputs into the front-end 41 a,b includes eight or fewer services.

The front-ends 41 a, b may then further sub-divide the L band inputsusing 1:4 L band splitters 42 a, 42 b, 42 c, and 42 d. Once subdivided,the L band signals may pass into four banks 44 a, 44 b, 44 c, and 44 dof dual tuner links. Each of the dual tuner links within the banks 44a-44 d may be configured to tune to two services within the L bandsignals received by that individual dual tuner links to produce SPTS.Each of the dual tuner links may then transmit the SPTS to one of thelow-voltage differential signaling (“LVDS”) drivers 48 a, 48 b, 48 c,and 48 d. The LVDS drivers 48 a-48 d may be configured to amplify thetransport signals for transmission to the back-end 52. In alternateembodiments, different forms of differential drivers and/or amplifiersmay be employed in place of the LVDS drivers 48 a-48 d. Otherembodiments may employ serialization of all of the transport signalstogether for routing to the back end 52.

As illustrated, the front-ends 41 a, b may also include microprocessors46 a and 46 b. In one embodiment, the microprocessors 46 a, b maycontrol and/or relay commands to the banks 44 a-44 d of dual tuner linksand the 1:4 L band splitters 42 a-42 d. The microprocessors 46 a, b maycomprise ST10 microprocessors produce by ST Microelectronics. Themicroprocessors 46 a, b may be coupled to LVDS receiver and transmittermodules 50 a and 50 b. The LVDS receiver/transmitter modules 50 a, b mayfacilitate communications between the microprocessors 46 a, b andcomponents on the back-end 52, as will be described further below.

Turning next to the back-end 52, the back-end 52 includes LVDS receivers54 a, 54 b, 54 c, and 54 d, which are configured to receive transportstream signals transmitted by the LVDS drivers 48 a-48 d. The back-end52 also includes LVDS receiver/transmitter modules 56 a and 56 b whichare configured to communicate with the LVDS receiver/transmitter modules50 a, b.

As illustrated, the LVDS receivers 54 a-54 d and the LVDSreceiver/transmitters 56 a, b are configured to communicate withtransport processors 58 a and 58 b. In one embodiment, the transportprocessors 58 a, b are configured to receive the SPTS produced by thedual tuner links in the front-ends 41 a, b. For example, in oneembodiment, the transport processors 58 a, b may be configured toproduce 16 SPTS. The transport processors 58 a, b may be configured torepack the SPTS into IP packets which can be multicast over the IPdistribution network 20. For example, the transport processors 58 a, bmay repackage DirecTV protocol packets into IP protocol packets and thenmulticast these IP packets on an IP address to one or more of the STBs22 a-22 n

The transport processors 58 a, b may also be coupled to a bus 62, suchas a 32 bit, 66 MHz peripheral component interconnect (“PCI”) bus.Through the bus 62, the transport processors 58 a, b may communicatewith a network processor 70, an Ethernet interface 84, and/or anexpansion slot 66. The network processor 70 may be configured to receiverequests for services from the STBs 22 a-22 n and to direct thetransport processors 58 a, b to multicast the requested services. In oneembodiment, the network processor is an IXP425 network processorproduced by Intel. While not illustrated, the network processor 70 mayalso be configured to transmit status data to a front panel of thesatellite gateway 14 a,b or to support debugging or monitoring of thesatellite gateway 14 a, b through debug ports.

As illustrated, the transport processors 58 a, b may also be coupled tothe Ethernet interface 68 via the bus 62. In one embodiment, theEthernet interface 68 is a gigabit Ethernet interface that provideseither a copper wire or fiber-optic interface to the IP distributionnetwork 20. In addition, the bus 62 may also be coupled to an expansionslot, such as a PCI expansion slot to enable the upgrade or expansion ofthe satellite gateway 14 a, b.

The transport processors 58 a, b may also be coupled to a host bus 64.In one embodiment, the host bus 64 is a 16-bit data bus that connectsthe transport processors 58 a, b to a modem 72, which may be configuredto communicate over the PSTN 28, as described above. In alternateembodiments, the modem 72 may also be coupled to the bus 62.

As described above, the satellite gateway 14 may transmit the IP packetsacross the IP distribution network 20 to the STBs 22 a-22 n. In oneembodiment, the satellite gateway 14 is configured to transmit IPpackets using two or more levels of security (e.g., encryption)depending on the capabilities of each of the STBs 22 a-22 n. Morespecifically, the satellite gateway 14 may be configured to multicastsatellite services to each one of the STBs 22 a-22 n at a security levelsupported by that particular STB. For example, if an STB operating at alower level of security (i.e., less encryption), requests a particularsatellite service (CNN, for example), the satellite gateway 14 maygenerate a multicast of CNN with the IP packets in the multicastencrypted at the lower security level. If, at the same time, another oneof the STBs 22 a-22 n operating at a higher level of security (i.e.,more encryption) also requests to receive CNN, the satellite gateway 14may generate another multicast of CNN using the higher level ofsecurity. In one embodiment, the satellite gateway 14 may be configuredto generate three different levels of security: network encryption,network encryption plus partial advanced encryption standard (“AES”),and network encryption plus full AES encryption (128-bit keyencryption). In alternate embodiments, however, alternate encryptiontechniques or security schemes may be employed.

As stated above, the satellite gateway 14 may be configured to generatedifferent multicasts to the STBs 22 a-22 n depending on the securitycapabilities supported by each of the STBs 22 a-22 n. In one embodiment,the satellite gateway 14 is configured to request the securitycapabilities supported by each of the STBs 22 a-22 n when thatparticular STB is coupled (via the IP distribution network 20) to thesatellite gateway 14. In this embodiment, the satellite gateway 14 maystore the security capabilities of each of the STBs 22 a-22 n and accessthese stored security capabilities when one of the STBs 22 a-22 nrequests satellite services from the satellite gateway 14. In anotherembodiment, the satellite gateway 14 may look at the hardware and/orsoftware characteristics of a particular one of the STBs 22 a-22 n whenthat particular STB requests satellite services from the satellitegateway 14. In yet another embodiment, the satellite gateway 14 may beconfigured to query the requesting STB 22 a-22 n about its securitycapabilities.

While the invention may be susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the invention is not intended to be limitedto the particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the invention as defined by the following appended claims.

What is claimed is:
 1. A method comprising: determining a first level ofsecurity supported by a first set top box responsive to a request fromthe first set top box, the first set top box being a part of a firstplurality of set top boxes supporting the first level of security;forming a first multicast directed to at least said first set top box,by encoding data received from a satellite service using the determinedfirst level of security supported by the first set top box, whereinfirst IP packets of said first multicast contain data from saidsatellite service that have been encoded using the determined firstlevel of security supported by the first plurality of set top boxes andwherein encoding to form the first multicast is performed afterdetermining the first level of security and continues as further data isreceived from said satellite service; transmitting the first IP encodedpackets to at least the first set top box in the first plurality of settop boxes; determining a second level of security supported by a secondset top box responsive to a request from the second set top box, thesecond set top box being a part of a second plurality of set top boxessupporting the second level of security; responsive to a determinationthat the second level of security supported by the second set top box isdifferent from the first level of security supported by the first settop box, forming a second multicast directed to at least said second settop box by encoding data received from said satellite service using thedetermined second level of security supported by the second set top box,wherein second IP packets of said second multicast contain data fromsaid satellite service that have been encoded using the determinedsecond level of security supported by the second plurality of set topboxes and wherein said encoding to form the second multicast isperformed after determining the second level of security supported bythe second set top box and continues as further data is received fromsaid satellite service; and transmitting the second encoded IP packetsto at least the second set top box in the second plurality of set topboxes, while the first plurality of set top boxes continues receivingthe first multicast containing the first encoded IP packets.
 2. Themethod of claim 1, wherein determining the level of security supportedby the second set top box comprises determining that the second set topbox supports network encryption.
 3. The method of claim 2, whereindetermining the level of security supported by the second set top boxcomprises determining that the second set top box supports partial128-bit encryption.
 4. The method of claim 2, wherein determining thelevel of security supported by the first set top box comprisesdetermining that the first set top box supports full 128-bit encryption.5. The method of claim 1, wherein encoding the first IP packetcomprising encoding an IP packet containing data from a digitalsatellite service.
 6. A satellite gateway comprising: a processorconfigured to determine a first level of security supported by a firstset top box responsive to a request from the first set top box, thefirst set top box being a part of a first plurality of set top boxessupporting the first level of security, the processor further configuredto determine a second level of security supported by a second set topbox responsive to a request from the second set top box, the second settop box being a part of a second plurality of set top boxes supportingthe second level of security; a transport processor configured to form afirst multicast directed to at least said first set top box, by encodingdata received from a satellite service using the determined first levelof security supported by the first set top box, wherein first IP packetsof said first multicast contain data from said satellite service thathave been encoded using the determined first level of security supportedby the first plurality of set top boxes and wherein encoding to form thefirst multicast is performed after determining the first level ofsecurity and continues as further data is received from said satelliteservice and, responsive to a determination that the second level ofsecurity supported by the second set top box is different from the firstlevel of security supported by the first set top box, form a secondmulticast directed to at least said second set top box by encoding datareceived from said satellite service using the determined second levelof security supported by the second set top box, wherein second IPpackets of said second multicast contain data from said satelliteservice that have been encoded using the determined second level ofsecurity supported by the second plurality of set top boxes and whereinsaid encoding to form the second multicast is performed afterdetermining the second level of security supported by the second set topbox and continues as further data is received from said satelliteservice; and a network interface configured to transmit the first IPencoded packets to at least the first set top box in the first pluralityof set top boxes and transmit the second encoded IP packets to at leastthe second set top box in the second plurality of set top boxes, whilethe first plurality of set top boxes continues receiving the firstmulticast containing the first encoded IP packets.
 7. The satellitegateway of claim 6, wherein the processor of the satellite gateway isconfigured to determine if the second set top box supports networkencryption.
 8. The satellite gateway of claim 6, wherein the processorof the satellite gateway is configured to determine if the second settop box supports partial 128-bit encryption.
 9. The satellite gateway ofclaim 6, wherein the processor of the satellite gateway is configured todetermine if the first set top box supports full 128-bit encryption. 10.The satellite gateway of claim 6, wherein the transport processor of thesatellite gateway is configured to encode the first IP packet with datafrom a digital satellite service.
 11. A satellite gateway comprising:processing means for determining a first level of security supported bya first set top box responsive to a request from the first set top box,the first set top box being a part of a first plurality of set top boxessupporting the first level of security; transport processing means forforming a first multicast directed to at least said first set top box,by encoding data received from a satellite service using the determinedfirst level of security supported by the first set top box, whereinfirst IP packets of said first multicast contain data from saidsatellite service that have been encoded using the determined firstlevel of security supported by the first plurality of set top boxes andwherein encoding to form the first multicast is performed afterdetermining the first level of security and continues as further data isreceived from said satellite service; network interface means fortransmitting the first IP encoded packets to at least the first set topbox in the first plurality of set top boxes; processing means fordetermining a second level of security supported by a second set top boxresponsive to a request from the second set top box, the second set topbox being a part of a second plurality of set top boxes supporting thesecond level of security; transport processing means for, responsive toa determination that the second level of security supported by thesecond set top box is different from the first level of securitysupported by the first set top box, forming a second multicast directedto at least said second set top box by encoding data received from saidsatellite service using the determined second level of securitysupported by the second set top box, wherein second IP packets of saidsecond multicast contain data from said satellite service that have beenencoded using the determined second level of security supported by thesecond plurality of set top boxes and wherein said encoding to form thesecond multicast is performed after determining the second level ofsecurity supported by the second set top box and continues as furtherdata is received from said satellite service; and network interfacemeans for transmitting the second encoded IP packets to at least thesecond set top box in the second plurality of set top boxes, while thefirst plurality of set top boxes continues receiving the first multicastcontaining the first encoded IP packets.
 12. The satellite gateway ofclaim 11 wherein determining the level of security supported by thesecond set top box comprises determining that the second set top boxsupports network encryption.
 13. The satellite gateway of claim 11wherein determining the level of security supported by the second settop box comprises determining that the second set top box supportspartial 128-bit encryption.
 14. The satellite gateway of claim 11wherein determining a level of security supported by the first set topbox comprises determining that the first set top box supports full128-bit encryption.